Add an about:flag to support alternative data saver features

chrome/browser/flag_descriptions.cc

Index: chrome/browser/flag_descriptions.cc
diff --git a/chrome/browser/flag_descriptions.cc b/chrome/browser/flag_descriptions.cc
index a05be8ee7f43a031a9f406ff54c3e219e09e8529..9401e5af69831ae7a00a4bc18710cb836f53f475 100644
--- a/chrome/browser/flag_descriptions.cc
+++ b/chrome/browser/flag_descriptions.cc
@@ -1162,6 +1162,16 @@ const char kEnableDataReductionProxyLitePageDescription[] =
     "shown instead of image placeholders when Lo-Fi is on. Data Saver and "
     "Lo-Fi must be enabled for lite pages to be shown.";
 
+const char kDataReductionProxyServerAlternative[] =
+    "Use alternative server configuration";

[buettner, 2017/05/23 23:32:13]

Just curious, but why are there three descriptions that say essentially the same
thing using slightly different words?

[RyanSturm, 2017/05/24 16:16:03]

1) what the text in the drop down says
2) What the bold name of the flag is
3) what the text below the name says

I am completely open to suggestions (for instance changing the drop down text to
just "alternative" to match the exp header" or changing the name to something
shorter "Alternative Data Saver back end.")

+
+const char kEnableDataReductionProxyServerExperimentName[] =
+    "Use an alternative Data Saver back end configuration.";
+
+const char kEnableDataReductionProxyServerExperimentDescription[] =
+    "Enable a different approach to saving data by configuring the back end "
+    "server";
+
 const char kDataReductionProxyCarrierTestName[] =
     "Enable a carrier-specific Data Reduction Proxy for testing.";